1986 

  1987 def debugstacktrace(msg='stacktrace', skip=0, f=sys.stderr):

  1988     '''Writes a message to f (stderr) with a nicely formatted stacktrace.

  1989     Skips the 'skip' last entries.

  1990     It can be used everywhere and do intentionally not require an ui object.

  1991     Not be used in production code but very convenient while developing.

  1992     '''

  1993     f.write('%s at:\n' % msg)

  1994     entries = [('%s:%s' % (fn, ln), func)

  1995         for fn, ln, func, _text in traceback.extract_stack()[:-skip - 1]]

  1996     if entries:

  1997         fnmax = max(len(entry[0]) for entry in entries)

  1998         for fnln, func in entries:

  1999             f.write(' %-*s in %s\n' % (fnmax, fnln, func))

  2000 

  2001 # convenient shortcut

  2002 dst = debugstacktrace